A generic self-locking seat belt retractor for a motor vehicle is known from DE 10 2006 033 543 A1. The basic attempt is to keep the noise development in seat belt retractors as low as possible in order to meet the motor vehicle manufacturers' requirements, particularly for higher class motor vehicles. The vehicle-sensitive sensor device has proven to be an important source of noise in the seat belt retractor. The vehicle-sensitive sensor device has a mass supported in a housing that carries out small movements in the presence of vibrations and thus produces rattling noises. In order to solve this problem, it is proposed in DE 10 2006 0333 543 A1 to mount the vehicle-sensitive sensor in a floating manner in respect of the housing. The floating mount of the vehicle-sensitive sensor can, however, be problematic insofar as, for proper functionality, the vehicle-sensitive sensor must be arranged on the locking device and on the control device of the seat belt retractor with very high accuracy. The floating mount proposed for reducing the noise development should therefore not cause the deviation of the position of the sensor from the its specified position; consequently, the floating mount must be produced with very high accuracy. Furthermore, the floating mount must be made of a particular material, which has the necessary characteristics for implementing the floating mount. In general, the more complex production of the floating mount results in a more expensive seat belt retractor.